DE102014219682B4 - Shim coil device and a magnetic resonance coil system with a Shimspulenvorrichtung - Google Patents

Abstract

Shim coil apparatus, in particular for compensation of basic magnetic field im-homogeneities during a medical magnetic resonance imaging of a breast (24) of a patient (15), comprising a housing unit (107, 203, 303, 804) having a support surface (110, 202, 805) which an overlay on a patient (15), and at least one shim coil element (108, 201, 304, 401, 501, 601, 701, 801) having a shim coil axis (109, 204, 402, 502, 604, 703, 802) wherein the shim coil device (102, 200, 302, 400, 500, 600, 700, 800) can be arranged on the patient (15) such that the at least one shim coil axis (109, 204, 402, 502, 604, 703, 802 ) has an inclination angle α to the bearing surface (110, 202, 805) and / or to a patient surface (26), where α ≥ 45 ° and α ≤ 135 °, characterized by a plurality of shim coil elements (601, 801), which in an am Patients (15) arranged state of the shim coil device (600, 800) in the direction (602) of a Longitudinal extension of the patient (15) are arranged one after the other.

Description

The present invention relates to a shim coil device, in particular for compensation of basic magnetic field inhomogeneities during a medical magnetic resonance imaging of a patient's chest, comprising a housing unit with a support surface, which is designed to rest on a patient, and at least one shim coil element with a shim coil axis.

Imaging in magnetic resonance imaging is based on the spins of atomic nuclei aligned in a basic magnetic field. For many users, homogeneity of the basic magnetic field is of crucial importance for image quality, especially for spatial registration of the images.

Due to an anatomy of the human body and its magnetic properties, such as a spatial distribution of a magnetic susceptibility arise when the patient is introduced into a basic magnetic field area, basic magnetic field inhomogeneities. For example, in female patients whose breast is being examined in a magnetic resonance system, these basic magnetic field inhomogeneities occur in areas that are preferably along a longitudinal extension of the patient below the chest wall located thorax. The magnetic resonance examination preferably takes place in the prone position of the patient, in particular of a female patient. During magnetic resonance imaging of the patient's chest, a deviation from the basic magnetic field may be so great that imaging techniques based on high basic magnetic field homogeneity, such as spectral fat saturation and / or EPI (echo planar imaging) and / or magnetic resonance spectroscopy, are described here fail and / or image quality problems arise. In addition, such inhomogeneities are usually spatially localized such that in magnetic resonance systems with incorporated shim coil elements that are part of the gradient coil, these inhomogeneities can not be corrected.

From the DE 10 2011 081 039 A1 is a local coil arrangement with integrated shim conductor. In this case, the local coil arrangement has a single shim conductor.

The DE 10 2013 214 125 A1 discloses an embodiment of a local shim coil arrangement for compensating the magnetic inhomogeneity of an MR system. The shimsule assembly is disposed within a local coil, the shim coil assembly having four shim coils. The four shim coils are in this case arranged laterally next to the breast pots of the local coil.

The present invention is based in particular on the object of enabling a particularly simple and efficient compensation of inhomogeneities of a basic magnetic field, in particular during a breast examination. The object is solved by the features of the independent claims. Advantageous embodiments are described in the subclaims.

The invention is based on a shim coil device, in particular for compensation of basic magnetic field inhomogeneities during a medical magnetic resonance imaging of a patient's chest, comprising a housing unit with a support surface which is designed to rest on a patient, and at least one shim coil element with a shim coil axis.

It is proposed that the shim coil device can be arranged on the patient in such a way that the at least one shim coil axis has an angle of inclination α to the support surface and / or to a patient surface, where α ≥ 45 ° and α ≦ 135 °. According to the invention, the shim coil device has a plurality of shim coil elements which, in a state of the shim coil device arranged on the patient, are arranged one after the other in the direction of a longitudinal extension of the patient. As a result, a simple and efficient compensation of a basic magnetic field inhomogeneity during a magnetic resonance examination of a breast can be achieved particularly advantageously. In particular, by means of the shim coil device, an inhomogeneity of the basic magnetic field in a region, in particular in a transition from a breast to a thorax of the patient, can be at least partially compensated. Due to this, a diagnostic significance in the acquired magnetic resonance images can also be increased since a clear separation of different tissue types in the magnetic resonance images can take place. Alternatively or additionally, a simple assignment of differently displayed areas in the magnetic resonance images to different types of tissue can also take place.

In this case, the at least one shim coil axis preferably has an angle of inclination α, where α ≥ 35 ° and α ≤ 125 °, for Support surface and / or to a patient surface. Particularly advantageous here, the at least one Shimspulenachse an inclination angle α where α ≥ 25 ° and α ≤ 115 ° to the support surface and / or to a patient surface. In this case, the at least one shim coil axis particularly advantageously has an angle of inclination α, where α ≥ 15 ° and α ≦ 105 °, to the support surface and / or to a patient surface.

Particularly preferably, the at least one Shimspulenachse an inclination angle α from 90 ° to the support surface and / or to a patient surface. An angle of inclination α of 90 ° should be understood to mean an angle of 90 ° plus a tolerance range, the tolerance range being a maximum of ± 10 ° and particularly preferably a maximum of ± 5 °.

In this context, a shim coil axis should be understood to mean, in particular, an axis of the at least one shim coil element of the shim coil device, which is preferably aligned perpendicular to a flow direction of a shim current flowing within the at least one shim coil element. Furthermore, a patient's surface should be understood as meaning, in particular, a surface of the patient on which preferably the shim coil device rests and / or rests on the patient during medical magnetic resonance imaging and / or on which the patient rests.

Alternatively or additionally, in a position of the patient positioned within a magnetic resonance device, on which the shim coil device is arranged, the at least one shim coil axis has an angle of inclination β to a basic magnetic field direction of a magnetic resonance apparatus, wherein β ≥ 45 ° and β ≤ 135 °. In this case, the at least one shim coil axis preferably has an angle of inclination β , where β ≥ 35 ° and β ≤ 125 °, to the basic magnetic field direction of the magnetic resonance apparatus. Particularly advantageous here, the at least one Shimspulenachse an inclination angle β , where β ≥ 25 ° and β ≤ 115 °, to the basic magnetic field direction of the magnetic resonance apparatus. Particularly advantageous here, the at least one Shimspulenachse an inclination angle β , where β ≥ 15 ° and β ≤ 105 °, to the basic magnetic field direction of the magnetic resonance apparatus. Particularly preferably, the at least one Shimspulenachse an inclination angle β of 90 ° to the basic magnetic field direction of the magnetic resonance apparatus. At a tilt angle β of 90 ° is to be understood here as an angle of 90 ° plus a tolerance range, wherein the tolerance range is a maximum of ± 10 ° and more preferably a maximum of ± 5 °. By means of this embodiment of the invention, a simple and efficient compensation of a basic magnetic field inhomogeneity can be achieved particularly advantageously during a magnetic resonance examination of a breast. In particular, by means of the shim coil device, an inhomogeneity of the basic magnetic field in one region, in particular in a transition from breast to thorax of the patient, can be at least partially compensated. Due to this, a diagnostic significance in the acquired magnetic resonance images can also be increased since a clear separation of different tissue types in the magnetic resonance images can take place. Alternatively or additionally, a simple assignment of differently displayed areas in the magnetic resonance images to different types of tissue can also take place.

In an advantageous development of the invention, it is proposed that the at least one shim coil element is arranged in a position of the shim coil device positioned on the patient in such a way that a region of a patient which has a disturbing effect on a homogeneity of a basic magnetic field is covered to a maximum of 50%. In this way it is advantageously possible to prevent an impairment of a breast examination due to the shim coil device, in particular by a local shimming magnetic field induced by shim currents. The shim coil device is preferably arranged on the patient during a breast examination in such a way that the area to be examined, in particular the chest region of the patient, is not covered by the shim coil element and also the region of the patient, which interferes with a homogeneity of a basic magnetic field, from the shim coil device, in particular of which at least one shim coil element is covered to a maximum of 50%. Preferably, however, the shim coil apparatus for a breast exam is disposed on the patient such that the shim coil apparatus and the area of the patient interfering with a homogeneity of a basic magnetic field together on a same side of the patient's chest, for example, a head-side or a foot-side , arranged on the patient. For example, the at least one shim coil element can be arranged at a distance from the patient's breast of preferably 2 cm to 15 cm. Particularly advantageously, the at least one shim coil element covers the region of the patient which causes the disturbance of the homogeneity of the basic magnetic field to a maximum of 40%. Particularly advantageously, the at least one shim coil element covers the region of the patient which causes the disturbance of the homogeneity of the basic magnetic field to a maximum of 30%. Particularly advantageously, the at least one shim coil element covers the region of the patient which causes the disturbance of the homogeneity of the basic magnetic field to a maximum of 20%, and particularly preferably to a maximum of 10%.

Particularly advantageously, the at least one shim coil element has a circular form or an oval shape or a rectangular shape or a square shape or a spiral shape. This also makes an advantageous compensation of a Basic magnetic field inhomogeneity can be achieved during a magnetic resonance examination of a breast.
In a further embodiment of the invention, it is proposed that the at least one shim coil element is arranged at a distance from the support surface of 0 cm to 2 cm. Alternatively or additionally, the at least one shim coil element can also be arranged at a distance from the contact surface, wherein the distance can correspond to half the depth of a breast coil receiving region of a breast coil device. As a result, an ideal and / or optimal distance between the at least one shim coil element and the patient can be set, so that a particularly efficient compensation of a basic magnetic field inhomogeneity can be achieved during a magnetic resonance examination of a breast.

In a further embodiment of the invention, the shim coil device may comprise a plurality of shim coil elements arranged one after the other in a state of the shim coil device arranged on the patient in a direction which is aligned transversely to a longitudinal extent of the patient. Alternatively or additionally, the shim coil device can have a plurality of shim coil elements, which are arranged one after the other in a state of the shim coil device arranged on the patient in the direction of a longitudinal extension of the patient. Alternatively or additionally, the shim coil device may comprise a plurality of shim coil elements, which are arranged offset to one another in a direction of the shim coil device arranged on the patient in a direction from the shim coil elements to the patient. In this context, in particular, two or more shim coil elements, preferably two to a maximum of 15 shim coil elements, preferably two to a maximum of ten shim coil elements and particularly preferably two to a maximum of five shim coil elements are to be understood by a plurality of shim coil elements.

Due to this embodiment of the invention with the several shim coil elements, individual, in particular patient-specific, magnetostatic conditions during the magnetic resonance imaging of the patient's breast can advantageously be taken into account on account of the multiple shim coil elements. For example, such an asymmetrical design of a chest region of the patient and / or an asymmetric position of organs, for example the lungs and / or the heart, of the patient in the compensation of the basic magnetic field inhomogeneity during the magnetic resonance examination can be taken into account and the individual shim coil elements adjusted accordingly and / or controlled. In particular, different shim currents can flow through the individual shim coil elements in order to compensate the basic magnetic field inhomogeneity during the magnetic resonance examination. In this case, the shim coil elements can also be arranged offset to one another in the direction of the longitudinal extension of the patient and / or in a direction transverse to the longitudinal extension of the patient.

In a further embodiment of the invention, the shim coil device can also have a drive unit, wherein the individual shim coil elements can be controlled separately from one another by means of the drive unit. In this way, individual, in particular patient-specific, magnetostatic conditions during the magnetic resonance imaging of the patient's breast can be taken into account particularly easily and specifically in a compensation of basic magnetic field inhomogeneities. In particular, the same shim coil device can in this case always be used for different patients with different individual magnetostatic circumstances, since an adaptation to the patient can take place by activating the individual shim coil elements and / or setting individual shim currents in the individual shim coil elements.

Furthermore, the invention is based on a magnetic resonance coil system with a local breast coil device and a shim coil device, the shim coil device having a housing unit with a bearing surface, which is designed to rest on a patient, and at least one shim coil element with a shim coil axis and the shim coil device in such a manner Patients can be arranged that the at least one Shimspulenachse a tilt angle α to the support surface and / or to a patient surface, where α ≥ 45 ° and α ≤ 135 °.

As a result, a simple and efficient compensation of a basic magnetic field inhomogeneity during a magnetic resonance examination of a breast can be achieved particularly advantageously. In particular, by means of the shim coil device, an inhomogeneity of the basic magnetic field in one region, in particular in a transition from breast to thorax of the patient, can be at least partially compensated. Due to this, a diagnostic significance in the acquired magnetic resonance images can also be increased since a clear separation of different tissue types in the magnetic resonance images can take place. Alternatively or additionally, a simple assignment of differently displayed areas in the magnetic resonance images to different types of tissue can also take place.

The advantages of the magnetic resonance coil system according to the invention essentially correspond to the advantages of the shim coil device according to the invention, which are carried out in advance in detail. Features, advantages, or alternative embodiments mentioned herein may also be applied to the other claimed subject matter, and vice versa.

Furthermore, it is proposed that the local breast coil device and the shim coil device can be arranged one after the other in the direction of a longitudinal extension of the patient. Here, shim coil device may be separate or separate from the local breast coil device. Alternatively, the shim coil device may also be integrated within the local breast coil device. Furthermore, the shim coil device can be arranged on the patient in the direction of the longitudinal extent on a side of the local breast coil device facing the patient or can be arranged on the patient in the direction of longitudinal extension on a side of the local breast coil device facing the patient's feet.

Further advantages, features and details of the invention will become apparent from the embodiment described below and with reference to the drawings.

• 1 eine medizinische Bildgebungsvorrichtung mit einem Magnetresonanzspulensystem in einer schematischen Darstellung,
• 2 ein Magnetresonanzspulensystem mit einer Shimspulenvorrichtung in einem am Patienten positionierten Zustand in einer schematischen Darstellung,
• 3 ein Magnetresonanzspulensystem mit einer alternativen Ausgestaltung einer Shimspulenvorrichtung in einem am Patienten positionierten Zustand in einer schematischen Darstellung,
• 4 ein weiteres Ausführungsbeispiel des Magnetresonanzspulensystem in einer schematischen Darstellung,
• 5 ein weiteres alternatives Ausführungsbeispiel einer Shimspulenvorrichtung in einer schematischen Darstellung,
• 6 ein weiteres alternatives Ausführungsbeispiel einer Shimspulenvorrichtung in einer schematischen Darstellung,
• 7 ein weiteres alternatives Ausführungsbeispiel einer Shimspulenvorrichtung in einer schematischen Darstellung,
• 8 ein weiteres alternatives Ausführungsbeispiel einer Shimspulenvorrichtung in einer schematischen Darstellung und
• 9 ein weiteres alternatives Ausführungsbeispiel einer Shimspulenvorrichtung in einer schematischen Darstellung.

Show it:

• 1 a medical imaging device with a magnetic resonance coil system in a schematic representation,
• 2 a magnetic resonance coil system with a shim coil device in a patient-positioned state in a schematic representation,
• 3 a magnetic resonance coil system with an alternative embodiment of a shim coil device in a patient-positioned state in a schematic representation,
• 4 a further embodiment of the magnetic resonance coil system in a schematic representation,
• 5 a further alternative embodiment of a shim coil device in a schematic representation,
• 6 a further alternative embodiment of a shim coil device in a schematic representation,
• 7 a further alternative embodiment of a shim coil device in a schematic representation,
• 8th a further alternative embodiment of a Shimspulenvorrichtung in a schematic representation and
• 9 a further alternative embodiment of a Shimspulenvorrichtung in a schematic representation.

In 1 is a magnetic resonance device 10 shown schematically. The magnetic resonance device 10 includes a magnet unit 11 , which is a superconducting fundamental magnet 12 for generating a strong and in particular constant basic magnetic field. The basic magnetic field has a basic magnetic field direction 13 on. In addition, the magnetic resonance device has 10 a patient receiving area 14 on to a recording of a patient 15 , The patient reception area 14 in the present embodiment is cylindrical and in a circumferential direction of the magnet unit 11 surrounded by a cylinder. Basically, however, is a different training of the patient receiving area 14 at any time conceivable. The patient 15 can by means of a patient support device 16 the magnetic resonance apparatus 10 in the patient receiving area 14 be pushed.

The magnet unit 11 also has a gradient coil unit 17 for generation of magnetic field gradients used for spatial coding during imaging. The gradient coil unit 18 is by means of a gradient control unit 18 the magnetic resonance apparatus 10 controlled. The magnet unit 11 further comprises a radio frequency antenna unit 19 to an excitation of a polarization, which is in the of the basic magnet 12 set generated magnetic field. The high-frequency antenna unit 19 is from a high frequency antenna controller 20 the magnetic resonance apparatus 10 controlled and radiates radiofrequency magnetic resonance sequences in an examination room, essentially from a patient receiving area 14 the magnetic resonance apparatus 10 is formed.

To a control of the basic magnet 12 , the gradient controller 18 and for controlling the high frequency antenna control unit 20 has the magnetic resonance device 10 a system controller 21 on. The system controller 21 centrally controls the magnetic resonance device 10 such as performing a predetermined imaging gradient echo sequence. It also includes the system controller 21 an evaluation unit not shown in detail for an evaluation of medical image data, which are detected during the magnetic resonance examination. Control information, such as imaging parameters, as well as reconstructed magnetic resonance images may be displayed on a display unit 22 , for example on at least one monitor, the magnetic resonance apparatus 10 for a medical operator. Furthermore, the magnetic resonance device 10 an input unit 23 by means of which information and / or parameters can be input during a measuring operation by the medical operating staff.

The magnetic resonance device 10 further comprises a local breast coil device 101 and a shim coil device 102 on that leading to a magnetic resonance coil system 100 are arranged. For a breast exam is the patient 15 , especially a female patient 15 in a prone position on the patient support device 16 positioned, with a chest 24 of the patient 15 within the local breast coil device 101 is arranged, as well as in the 1 and 2 you can see. This is the local breast coil device 101 directly on the patient support device 16 arranged. For magnetic resonance imaging of the breast includes an imaging area 103 , especially a field of view, the chest 24 of the patient 15 and also at least partially the region causing the disturbance of the homogeneity of the basic magnetic field 25 of the patient 15 ,

The breast coil device 101 has a breast coil receiving area 104 on, leading to a recording of the breast 24 of the patient 15 is designed. Around the breast coil receiving area 104 are breast coil antennas 105 arranged. In one at the patient support device 16 arranged state of the magnetic resonance coil system 100 are the local breast coil device 101 and the shim coil device 102 successively in a longitudinal extension of the patient support device 16 at the patient support device 16 arranged. In addition, the local breast coil device 101 and the shim coil device 102 formed by separate units, each with its own housing unit 106 . 107 have and are formed separately from each other.

In the present embodiment, the shim coil device 102 related to the patient 15 foot side to the local breast coil device 101 arranged. In principle, a deviating arrangement, in particular one related to the patient 15 Head-side arrangement of the shim coil device 102 to the local breast coil device 101 , be possible at any time.

The shim coil device 102 serves to compensate for basic magnetic field inhomogeneities during the acquisition of image data. These basic magnetic field inhomogeneities are made by the patient 15 caused. In particular, areas 25 in a transition from the chest 24 of the patient 15 to a thorax of the patient 15 lead to particularly strong basic magnetic field inhomogeneities, which affect detection of magnetic resonance image data of the chest area. This affects the imaging of the breast 24 especially negative, since this area 25 usually at least partially imaged, in order to increase security for a diagnosis. By means of the shim coil device 102 These basic magnetic field inhomogeneities can be compensated during imaging. Also the shim coil device 102 is for the compensation of basic magnetic field inhomogeneities during magnetic resonance imaging of the breast 24 of the patient 15 directly on the patient support device 16 and on the patient 15 arranged.

The shim coil device 102 has at least one shim coil element 108 on. In the present embodiment of 2 has the shim coil device 102 a single shim coil element 108 with a shim coil axis 109 on. The shim coil axis 109 is perpendicular to a current direction of a shim current passing through the shim coil element 108 during a compensation of basic magnetic field inhomogeneities flows aligned. Furthermore, the shim coil device 102 a housing unit 107 on which the shim coil device 102 shields to the outside. The housing unit 107 includes a support surface 110 , by means of which the shim coil device 102 on a patient 15 can lie on or on the patient 15 for a magnetic resonance examination of the breast 24 rests. The bearing surface 110 the shim coil device 102 is in one at the patient support device 16 arranged and / or positioned state on one of the patient support device 16 facing away from the shim coil device 102 arranged.

The shim coil element 108 in 2 is parallel to the support surface 110 arranged. This is the Shimspulenachse 109 with a tilt angle α to the support surface 110 arranged, the angle of inclination α in the present embodiment is 90 °. Due to the fact that in one patient 15 positioned state of the shim coil device 102 this by means of the support surface 110 directly on the patient 15 rests, is thus the Shimspulenachse 109 of the shim coil element 108 also with the inclination angle α to a patient surface 26 arranged, wherein the inclination angle α to the patient surface 26 is also 90 °. An angle of inclination α of 90 ° means an angle of 90 ° plus a tolerance range, the tolerance range being a maximum of ± 10 ° and particularly preferably a maximum of ± 5 °. Is the patient 15 on the patient support device 16 positioned and located with the patient 15 within the patient reception area 14 so is the shim coil axis 109 With a tilt angle β arranged to the basic magnetic field direction, wherein the inclination angle β in the present embodiment is 90 °. It is under a tilt angle β 90 ° an angle of 90 ° plus a tolerance range to understand, the tolerance range is a maximum of ± 10 ° and more preferably a maximum of ± 5 °.

The shim coil device 102 is in one patient 15 arranged state so on the patient 15 arranged that area 25 of the patient 15 , which interferes with the homogeneity of the basic magnetic field, to a maximum of 50% of the Shimspulenelement 108 is covered. Particularly advantageously, this covers at least one shim coil element 108 the region causing the disturbance of the homogeneity of the basic magnetic field 25 of the patient 15 to a maximum of 40%. Particularly advantageously, this covers at least one shim coil element 108 the region causing the disturbance of the homogeneity of the basic magnetic field 25 of the patient 15 to a maximum of 30%. Particularly advantageously, this covers at least one shim coil element 108 the region causing the disturbance of the homogeneity of the basic magnetic field 25 of the patient 15 to a maximum of 20%, and more preferably to a maximum of 10%.

In particular, the Shimspulenachse 109 of the shim coil element 108 runs next to the area causing the disturbance of the homogeneity of the basic magnetic field 25 of the patient 15 through the patient 15 , In the state where the shim coil device 102 on the patient 15 is disposed, is preferably the disturbance of the homogeneity of the basic magnetic field causing region 25 of the patient 15 in the direction 111 a longitudinal extension of the patient 15 between the chest 24 of the patient 15 and the shim coil device 102 , A distance 112 of the shim coil element 108 to the patient's chest 15 is preferably between 2 cm and 15 cm.

The shim coil element 108 within the shim coil device 102 is at a distance 113 to the contact surface 110 arranged, with the distance 113 has a value between 0 cm and 2 cm. Alternatively or additionally, the distance 113 of the shim coil element 108 to the contact surface 110 the shim coil device 102 also on the local breast coil device 101 be coordinated. Here, the distance 113 a half depth 114 of the breast coil intake area 104 correspond.

The shim coil element 108 in 2 can have a circular shape, as in 5 is also shown. Alternatively, the shim coil element 108 also an oval training ( 8th ) or a rectangular training ( 6 ) or have a square shape or a spiral formation.

As in 2 is seen through the shim coil element 108 a shim field 115 generated in a region of the shim coil element 108 essentially perpendicular to the support surface 110 is aligned. Thus, an influence of the basic magnetic field by the shim field 115 prevented.

In the area causing the disturbance of the homogeneity of the basic magnetic field 25 of the patient 15 the shim field runs 115 perpendicular and / or nearly perpendicular to the shim coil axis 109 and thus also parallel and / or nearly parallel to the basic magnetic field. Thereby, in an operating state of the shim coil device 102 a basic magnetic field inhomogeneity in the region causing the disturbance of the homogeneity of the basic magnetic field 25 of the patient 15 at least partially compensated and / or almost completely compensated.

In the chest area of the patient 15 the shim field runs 115 again essentially perpendicular to the basic magnetic field direction 13 and thus does not affect the basic magnetic field. An area of the patient 15 sitting at one of the local breast coil device 101 opposite side of the shim coil device 101 is outside the imaging area 103 arranged for the magnetic resonance imaging, so that here is a possible influence of the basic magnetic field by the shim field 115 can be disregarded.

The shim coil device 102 also has a drive unit 116 on, which leads to a control of the Shimspulenelements 108 is designed to compensate for basic magnetic field imbalances during medical magnetic resonance imaging. The drive unit 116 is inside the system controller 21 the magnetic resonance apparatus 10 like this in 1 can be seen, arranged. By means of a data transmission unit 117 is the shim coil device 102 with the control unit 116 connected, wherein the data transmission unit 117 may also be designed for a wireless and / or a wireless data transmission.

In 3 is an alternative embodiment of a shim coil device 200 shown. Substantially identical components, features and functions are basically numbered by the same reference numerals. The following description is essentially limited to the differences from the embodiment in FIG 2 , wherein with respect to the same components, features and functions on the description of the embodiment in 2 is referenced.

The shim coil device 200 in 3 has a shim coil element 201 on that with respect to a bearing surface 202 a housing unit 202 the shim coil device 200 inclined within the shim coil device 200 is arranged. This also indicates a Shimspulenachse 204 of the shim coil element 201 a tilt angle α to the contact surface 202 and / or to a patient surface 26 of the patient 15 on, where α ≥ 45 ° and α ≤ 135 °. Preferably, in this case, the Shimspulenachse 204 an inclination angle α, where α ≥ 35 ° and α ≦ 125 °, to the bearing surface 202 and / or to the patient surface 26 of the patient 15 on. Particularly advantageous here is the Shimspulenachse 204 an inclination angle α, where α ≥ 25 ° and α ≤ 115 °, to the bearing surface 202 and / or to the patient surface 26 of the patient 15 on and particularly preferred in this case has the Shimspulenachse 204 a tilt angle α , where α ≥ 15 ° and α ≤ 105 °, to the bearing surface 202 and / or to the patient surface 26 of the patient 15 on.

Thus, the Shimspulenachse 204 of the shim coil element 201 a tilt angle β to the basic magnetic field direction 13 where β ≥ 45 ° and β ≤ 135 °. Preferably, in this case, the Shimspulenachse 204 an inclination angle β, where β ≥ 35 ° and β ≦ 125 °, to the basic magnetic field direction 13 on. Particularly advantageous here is the Shimspulenachse 204 an inclination angle β, where β ≥ 25 ° and β ≦ 115 °, to the basic magnetic field direction 13 on and particularly preferred in this case has the Shimspulenachse 204 a tilt angle β where β ≥ 15 ° and β ≤ 105 °, to the basic magnetic field direction 13 on.

For a further embodiment of the shim coil device 200 becomes the remarks to the 2 directed. Thus, the shim coil element 201 a circular training ( 5 ) or an oval formation ( 8th ) or a rectangular training ( 6 ) or have a square shape or a spiral formation.

Also an arrangement and / or position of the shim coil device 200 with respect to the local breast coil device 101 and / or the patient support device 16 and / or to the patient 15 corresponds to the comments on 2 , so that also a functioning of in 3 shown Shimspulenvorrichtung 200 an operation of in 1 shown Shimspulenvorrichtung 102 equivalent. Likewise, the arrangement of the shim coil device 200 within the magnetic resonance coil system 100 on the comments too 2 directed.

In 4 is an alternative embodiment of a magnetic resonance coil system 300 shown. Substantially identical components, features and functions are basically numbered by the same reference numerals. The following description is essentially limited to the differences from the embodiment in the 2 and 3 , wherein with respect to the same components, features and functions on the description of the embodiment in the 2 and 3 is referenced.

The magnetic resonance coil system 300 in 4 has a local breast coil device 301 and a shim coil device 302 on. The shim coil device 302 is within the local breast coil device 301 integrated. Here, the local breast coil device form 301 and the shim coil device 302 a common unit with a single housing unit 303 containing both the local breast coil device 301 as well as the shim coil device 302 surrounds.

The shim coil device 302 is in the present embodiment, the foot side to the local breast coil device 301 within the magnetic resonance coil system 300 arranged. Basically, a deviating arrangement, in particular a head-side arrangement of the shim coil device 302 with respect to the local breast coil device 301 within the magnetic resonance coil system 300 At any time without departing from the scope of the invention.

For a further embodiment of the shim coil device 302 becomes the remarks to the 2 directed. In particular for an embodiment of a shim coil element 304 and its location and / or position relative to the housing unit 303 and / or the patient support device 16 and / or the patient 15 and / or the basic magnetic field direction 13 will apply to the comments 2 and 3 directed.
In the 5 and 9 are further alternative embodiments of a shim coil device 400 . 500 . 600 . 700 . 800 shown. Substantially identical components, features and functions are basically numbered by the same reference numerals. The following description is essentially limited to the differences from the embodiment in the 2 to 4 , wherein with respect to the same components, features and functions on the description of the embodiment in the 2 to 4 is referenced.

In 5 is a section through the shim coil device 400 shown in a view from above. The shim coil device 400 has a single shim coil element 401 with a single shim coil axis 402 on. The shim coil element 401 has a circular formation.

In 6 is a section through the shim coil device 500 shown in a view from above. The shim coil device 500 has a single shim coil element 501 with a single shim coil axis 502 on. The shim coil element 501 has a rectangular shape.

In 7 is a section through the shim coil device 600 shown in a view from above. The shim coil device 600 has several shim coil elements 601 on, in the present embodiment, eight shim coil elements 601 are included. The individual shim coil elements 601 are arranged to a 2x4 shim coil matrix. Along one direction 602 parallel to a longitudinal extension of the patient 15 and / or the patient support device 16 in one on the patient 15 arranged state of the shim coil device 600 is a number of successively arranged Shimspulenelementen 601 two coil elements 601 , Along one direction 603 perpendicular to a longitudinal extension of the patient 15 and / or the patient support device 16 in one on the patient 15 arranged state of the shim coil device 600 is a number of successively arranged Shimspulenelementen 601 four coil elements 601 ,

The individual coil elements 601 have a circular formation. In addition, the individual shim coil elements 601 one shim coil axis each 604 on.

In 8th is a section through the shim coil device 700 shown in a view from above. The shim coil device 700 has several shim coil elements 701 on, wherein in the present embodiment, two Shimspulenelemente 701 are included. Along one direction 702 perpendicular to a longitudinal extension of the patient 15 and / or the patient support device 16 in one on the patient 15 arranged state of the shim coil device 700 is, the two coil elements 701 arranged one after the other.

The individual coil elements 701 have an oval shape. In addition, the individual shim coil elements 701 one shim coil axis each 703 on.

In 9 is a section through the shim coil device 800 shown, with the section along one direction 803 a distance from the shim coil device 800 to the patient 15 runs. The shim coil device 800 has several shim coil elements 801 on, wherein in the present embodiment, two Shimspulenelemente 801 are included. The individual shim coil elements 801 one shim coil axis each 802 on.

In that direction 803 are the two coil elements 801 offset from each other, so that the two coil elements 801 a different distance to a housing unit 804 , in particular a support surface 805 , and to the patient 15 respectively.

The in the 5 to 9 illustrated embodiments are intended only by way of example a variety of possible embodiments of the Shimspulenvorrichtung 400 . 500 . 600 . 700 . 800 suggest. The individual shim coil device 400 . 500 . 600 . 700 . 800 However, here are not on the illustrated numbers of Shimspulenelementen 401 . 501 . 601 . 701 . 801 limited and a different number of Shimspulenelementen 401 . 501 . 601 . 701 . 801 inside the shim coil device 400 . 500 . 600 . 700 . 800 anytime possible. Furthermore, there is also a form of the individual shim coil elements shown 401 . 501 . 601 . 701 . 801 is not limited to the examples shown and other, the expert appears to be reasonable embodiments are possible at any time.

For a further embodiment of the in the 5 to 9 illustrated Shimspulenvorrichtungen 400 . 500 . 600 . 700 . 800 becomes the remarks on the 2 to 4 directed. Also an arrangement and / or position of the shim coil devices 400 . 500 . 600 . 700 . 800 with respect to a local breast coil device 101 . 301 and / or the patient support device 16 and / or to the patient 16 and / or to the basic magnetic field direction 13 corresponds to the comments on the 2 to 4 , Likewise, the arrangement of the Shimspulenvorrichtungen 400 . 500 . 600 . 700 . 800 within the magnetic resonance coil system 100 . 300 on the remarks to the 2 to 4 directed.

A control of in 5 to 9 illustrated Shimspulenvorrichtungen 400 . 500 . 600 . 700 . 800 takes place by means of the drive unit 116 , Here, the individual shim coil elements 401 . 501 . 601 . 701 . 801 individually, in particular independently of each other, by means of the drive unit 116 be controlled.

Although the invention has been further illustrated and described in detail by the preferred embodiment, the invention is not limited by the disclosed examples, and other variations can be derived therefrom by those skilled in the art without departing from the scope of the invention.

Claims (14)

Shim coil device, in particular for a compensation of basic magnetic field inhomogeneities during a medical Magnetic resonance imaging of a breast (24) of a patient (15), comprising a housing unit (107, 203, 303, 804) with a bearing surface (110, 202, 805), which is designed to rest on a patient (15), and at least a shim coil element (108, 201, 304, 401, 501, 601, 701, 801) having a shim coil axis (109, 204, 402, 502, 604, 703, 802), the shim coil device (102, 200, 302, 400, 500, 600, 700, 800) can be arranged on the patient (15) such that the at least one shim coil axis (109, 204, 402, 502, 604, 703, 802) has an angle of inclination α to the support surface (110, 202, 805). and / or to a patient surface (26), where α ≥ 45 ° and α ≤ 135 °, characterized by a plurality of shim coil elements (601, 801) arranged in a state of the shim coil device (600, 800) arranged on the patient (15). in the direction (602) of a longitudinal extent of the patient (15) are arranged one after the other. Shim coil device after Claim 1 , characterized in that the at least one Shimspulenachse (109, 402, 502, 604, 703, 802) has an inclination angle α of 90 ° to the support surface (110, 805) and / or to a patient surface (26). Shim coil device according to one of the preceding claims, characterized in that in a positioned within a magnetic resonance device (10) position of the patient (15), on which the Shimspulenvorrichtung (102, 200, 302, 400, 500, 600, 700, 800) is arranged in that at least one shim coil axis (109, 204, 402, 502, 604, 703, 802) has an inclination angle β to a basic magnetic field direction (13) of the magnetic resonance apparatus (10), where β ≥ 45 ° and β ≤ 135 °. Shim coil device according to one of the preceding claims, characterized in that in a positioned within a magnetic resonance device (10) position of the patient (15) on which the shim coil device (102, 302, 400, 500, 600, 700, 800) is arranged, the at least one Shim coil axis (109, 402, 502, 604, 703, 802) has an inclination angle β of 90 ° to a basic magnetic field direction (13) of the magnetic resonance apparatus (10). Shim coil device according to one of the preceding claims, characterized in that the at least one shim coil element (108, 201, 304, 401, 501, 601, 701, 801) in a state of the shim coil device (102, 200, 302, 400, 500, 600, 700, 800) is arranged such that a region (25) of a patient (15), which interferes with a homogeneity of a basic magnetic field, is covered to a maximum of 50%. Shim coil device according to one of the preceding claims, characterized in that the at least one shim coil element (108, 201, 304, 401, 501, 601, 701, 801) has a circular shape or an oval shape or a rectangular shape or a square shape or a spiral shape Training has. Shim coil device according to one of the preceding claims, characterized in that the at least one Shimspulenelement (108, 201, 304, 401, 501, 601, 701, 801) with a distance (113, 205) to the support surface (110, 202, 805) of 0 cm to 2 cm is arranged. Shim coil device according to one of the preceding claims, characterized in that the at least one Shimspulenelement (108, 201, 304, 401, 501, 601, 701, 801) with a distance (113, 205) to the support surface (110, 202, 805) wherein the distance (113, 205) corresponds to half a depth (114) of a breast coil receiving region (104) of a breast coil device (101, 301). Shim coil device according to one of the preceding claims, characterized by a plurality of shim coil elements (601, 701, 801) arranged in a state of the shim coil device (600, 700, 800) arranged on the patient (15) in a direction (603, 702) transverse to a longitudinal extension of the patient (15) is aligned, are arranged one after the other. Shim coil device according to one of the preceding claims, characterized by a plurality of shim coil elements (801) which, in a state of the shim coil device (800) arranged on the patient (15), are offset in a direction (803) from the shim coil elements (801) to the patient (15) are arranged. Shim coil device according to one of the preceding claims, characterized by a drive unit (116), wherein the individual shim coil elements (601, 701, 801) can be controlled separately from one another by means of the drive unit (116). Magnetic resonance coil system comprising a local breast coil device (101, 301) and a shim coil device (102, 200, 302, 400, 500, 600, 700, 800), wherein the shim coil device (102, 200, 302, 400, 500, 600, 700, 800 ) is designed in particular for compensation of basic magnetic field inhomogeneities during a medical magnetic resonance imaging of a breast (24) of a patient (15) and a housing unit (107, 203, 303, 804) which forms a bearing surface (110, 202, 805) Support on a patient (15), and at least one Shimspulenelement (108, 201, 304, 401, 501, 601, 701, 801) having a shim coil axis (109, 204, 402, 502, 604, 703, 802), wherein the shim coil device (102, 200, 302, 400, 500 , 600, 700, 800) can be arranged on the patient (15) such that the at least one shim coil axis (109, 204, 402, 502, 604, 703, 802) has an angle of inclination α to the support surface (110, 202, 805) and or to a patient surface (26), where α ≥ 45 ° and α ≤ 135 °, characterized by a plurality of shim coil elements (601, 801) arranged in a state of the shim coil device (600, 800) arranged on the patient (15) Direction (602) of a longitudinal extension of the patient (15) are arranged one after the other. Magnetic resonance coil system according to Claim 12 , characterized in that the local breast coil device (101, 301) and the shim coil device (102, 200, 302, 400, 500, 600, 700, 800) can be arranged successively along a longitudinal extent of the patient (15). Magnetic resonance coil system according to one of Claims 12 or 13 characterized in that the shim coil device (302, 400, 500, 600, 700, 800) is integrated within the local breast coil device (301).

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